Tropical Storm Irene:
Reconnaissance aircraft investigated the tropical disturbance located east of the Leeward Islands late this afternoon and found a 50 mph tropical storm; therefore, Invest 97L has been upgraded to Tropical Storm Irene. Irene is tracking slightly north of due west at a forward speed of 22 mph. A ridge of high pressure to the north of Irene will steer the storm between due west and west-northwest through at least Tuesday. After that, global model guidance seems to be trending towards a flatter trough of low pressure and a stronger ridge of high pressure. Based on this, I still think Irene will track just south of Hispaniola rather than right over the island. This thinking is supported by both the GFS and European ensemble guidance, as well as the most recent GFDL model which actually forecasts a track right over Jamaica on Tuesday evening. Personally, I think Irene will shoot the gap between Jamaica and the south coast of Cuba on Tuesday night into Wednesday and then track across central and western Cuba late Thursday into early Friday. This track could then bring Irene very close to or right over Key West during Friday.

Beyond Friday, the model guidance varies on the potential routes Irene could take with an ultimate landfall anywhere between Mobile, Alabama and a track that takes Irene right along the western coast of Florida and inland near Cedar Key. Timeframe for this would be late Saturday into Sunday.

Satellite imagery this evening indicates that Irene is strengthening with deep convection really firing very near the center of the storm. Irene is expected to track across very warm ocean waters with favorable upper conditions. The intensity guidance forecasts that Irene will become a hurricane within the next 24 hours and I agree with this and think that Irene will be a hurricane by this time tomorrow or earlier. The intensity forecast for Irene becomes very difficult once it gets near Hispaniola and Cuba. If Irene tracks over Hispaniola, then significant weakening would occur and Irene would potentially impact Florida as a much weaker hurricane. Now, if Irene tracks south of Hispaniola and tracks across the flatter terrain of western Cuba, then Irene could be a very strong hurricane when it enters the eastern Gulf of Mexico. It should be pointed out that the most recent GFDL model forecasts that Irene will be an upper end Category 4 hurricane when it reaches the western Caribbean and southern Gulf of Mexico on Wednesday night. I think the GFDL model is overdoing the intensity, but, the potential is there for this to be a strong hurricane should it avoid land interaction.

Tropical Storm Warnings are in effect for Puerto Rico, the Virgin Islands and the Leeward Islands. For those of you that are under the Tropical Storm Warning, make sure you prepare for tropical storm conditions according to your Hurricane Disaster Plan. Mariners are strongly urged to make all necessary preparations to return to port, seek safe harbor and secure your craft.

Tropical storm conditions are expected across the Leeward Islands tonight into Sunday morning. Tropical storm conditions are expected to begin in the Virgin Islands and Puerto Rico on Sunday afternoon and will continue right into much of Monday. Hurricane conditions are possible in the Dominican Republic by Monday afternoon.

Total rainfall amounts of 4 to 8 inches are expected across the Leeward Islands, Puerto Rico and the Virgin Islands with the passage of Irene. These rainfall totals will cause flash floods and mudslides across the Tropical Storm Warning area.

I strongly urge all of our Crown Weather friends across the rest of the Caribbean, the central and eastern Gulf coast, the entire Florida Peninsula and the US Southeast coast north to Cape Hatteras to closely monitor this system and go over your hurricane preparedness kits and think about what you would do in case of Hurricane Watches & Warnings. I will be monitoring Tropical Storm Irene extremely closely and I will keep you all updated.

The next tropical weather discussion will be issued by 11 am EDT/10 am CDT Sunday morning.